Torsionally resilient coupling



Nov. 19, 1935. FAST 1 TORSIONALLY RESILIENT COUPLING Filed Nov. 12, 1931I 2 Sheets-Sheet 1 INVENTOR BY ATTORNEY I v Nov. 19, 1935. FAST2,021,718 I TORSIONALLY RESILIENT COUPLING 2 Sheets-Shet 2 Filed NOV.12, 1931 Patented Nov. 19, .1935

* UNITED STATES TORSIONALLY, RESILIENT COUPLING Gustave Fast,

Annapolis, Md.,, assignor to Gustave Fast Engineering Corporation,Annapolis, Md., a corporation of Maryland Application November 12, 1931,Serial No. 574,504

' 160mm. (01. 64-15) I This invention relates to coupling devices forconnecting the shafts of driving and driven machines, and has for itsobject the provision of means for preventing, damping, or reducing inamplitudethe oscillations which may be produced by variations in thetorque transmitted between such machines. If, asmay happen, thefrequency of any such oscillations set up by a variation in the torqueshould coincide with the natural frequency of the system, theoscillations will be amplified and may become of considerable amplitude,thereby subjecting the shafts and coupling to dangerous stresses. It isan important object of the present invention to provide means wherebythe excess energy made available for setting up shaft oscillations by anincrease or a decrease in torque of one or the other of the connected;machines may be partially absorbed, thereby damping the resultingoscillation of the system. For this purpose there has been provided atorsionally resilient connection between the driving and driven machineshaving a relatively great internal friction. The torsional resilience ofthe coupling releives' the stresses in the connected shafts while thefriction produces the desired damping and avoids I the production ofoscillations having the natural or a harmonic frequency of the system.

The invention has been illustrated as applied to a coupling of theself-aligning type, such as that disclosed in my Reissue Patent No.15,177, as well as to an ordinary coupling. However, the presentinvention may be applied equally well to other types of coupling, and Ido not wish to be limited to the particular application illustrated inthe accompanying drawings, in which:

Fig. 1 is a side view'of a self-aligning coupling to which the inventionhas been applied, partly insection and partly in elevation, withsuccessive parts broken away to reveal the interior construction; Fig. 2is a transverse vertical'section on the line 2-2 of Fig. 1, with certainportions broken away; and Fig. 3 is a fragmentary vertical longitudinalsection of a non-self-aligning or 1 ordinary coupling to whichthe'invention'has been applied. 7

Referring more particularly to the drawingsit will be seen (Fig. 1) thatthe self-aligning-coupling, with the present invention applied thereto,is substantially symmetrical. Therefore-the description will be limitedto the parts at one end of said coupling, it being understood thattheparts at the other end are substantially identical with those described.

The casing of the coupling consists of two members ll, securedlv rigidlytogether by means of bolts H to constitute, in effect, a unitarystructure. Two shafts I2 to be coupled aresubstan- 'tially in alignmentand each has secured thereto,

, by means of a key l3, ahub I4, one portion of the 5 periphery of whichis toothed as at H). A ring l6 surrounds the toothed portion of the hub:I4, and is provided, on its interior surface, with teeth ll, which meshwith the teeth l5.1 The teeth 15 and IT serve to transmit torque fromshaft to 10 coupling, and also provide theself-aligning feature, as ismore fully described in my earlier patent referred to above. I

The ring I6 is provided, on its outer surface, with helical teeth l8,which mesh with corresponding internal teeth l9 formed on theinnerSurface of the casing member ll. Teeth l8 on one of the rings 16 are ofopposite sense from those on the other ring. The teeth l8 and IS, inaddition to their other function to be presently described, serve totransmit torque between the ring I6 and the. casing member H, andthence, through similar meansto the. other shaft l2.

Between the two rings I6 is interposed a strong spring, shown in thepresent embodiment as comprising two series of continuous, unbrokenspring rings 20 and 2|. The cooperatingsurfaces, of

the rings 20 and 2| .arebeveled, as illustrated,

to provide a ca'mming action between them as they are shifted axially ina manner tobe explained. These rings are preferablyformed of steel orsimilar elastic or resilient material so that upon shifting the ringstogether axially the rings 20 will be stretched or expanded, while therings 2| will be compressed orcontracted. Energy will thus bestored inthese rings as the result oftheir relative movement toward each otherand released upon relative movement apart. The ends of the coupling areclosed'by the retaining members 22, whose purpose and operation have nodirect bearing upon the present invention, and are fully described ingmyearlier patent referred to above. v

From the foregoing description of the invention, its operation will bereadily understood. Assuming that the system is in operation, and theshafts and coupling are rotating at normal speed in a clockwise,direction, as viewed from the right end of Fig. 1, it is. apparent that,by reason of the cooperation of the helical teeth l8 and l 9 the ring 50I6 will have been thrust inward or toward the left in Fig. 1 to shiftthe rings 20 and 2| together to an amount dependent upon the torquetransmitted. When the elastic rings have been stressed to a sufllcientdegree, the irmer rings being com- 55 gagement between the teeth l8 andI9 will transmit the torque to the casing ll. At the opposite end theaction of the corresponding teeth will simply force the ring 16 againstthe retaining member 22 and the ring will be rotated by the casing. Ifthe rotation of the shafts were in the opposite direction, the ring H5at the right end of Fig. 1 would be forced against the retainer 22 whilethe ring at the opposite end would be shifted toward the right and wouldtend to squeeze the spring rings together in the same way. In the eventof a sudden increase in torque, under the conditions first assumed, thering I6 at the right will be rotated a certain additional amountrelative to the casing member I I, which rotation will cause the ring IEto move inward to a further extent against the tension of spring rings20 and 2|, resulting in the setting up of additional stresses and thestorage of greater energy in these rings. When the torque is decreased,the reverse movement of the ring IE will take place, and the pressurebetween the rings 20 and 2| will be relieved to a certain extent, butthe full amount of the energy stored in the rings 20 and 21 will not bereturned, since a considerable proportion of this energy will have beendissipated by the friction between the spring rings, between the ring 16and easing II and between the ring I6 and the adjacent ring 20.

It will be appreciated, therefore, that by use of the present inventionthe oscillations resulting from variations in torque may be greatlydamped, and the minor oscillations completely eliminated. therebypreventing the occurrence of dangerous stresses in the coupling, shafts,and associated machines.

In the construction illustrated in Fig. 3; the self-aligning feature hasbeen omitted from the coupling. The helical teeth I8 are formed upon thehub H, the separate ring l6 having been omitted. In this constructionthe hubs H are permitted the lateral movements imparted to the rings l6of the previous construction, the spring rings 20 and 2| beinginterposed directly between portions of the hubs II.

By reversing the direction of the helical teeth at opposite ends of thecoupling, in both forms of construction, i. e., by providing left handteeth at one end and right hand at the opposite end,the system isequipped for the same type of action in either direction of rotation ofthe shafts, as has been explained.

The terms and expressions employed in the foregoing are to be consideredas terms of description and not of limitation and the present inventionis not to be regarded as limited to the particular constructiondescribed and illustrated, but it is recognized that many modificationsthereof may be made within the scope of the appended claims.

What I claim is: H

1. In a device for coupling a driving and a driven shaft, a couplingmember, means for transmitting torque from the driving shaft to saidmember, said means and said member being provided with cooperating teethwhereby a relative rotative movement between said means and said memberis accompanied by a relative translational movement therebetween,resilient means opposing said relative translational movement, andmeansfor transmitting torque from said member to the driven shaft.

pressed and the outer rings stretched, the endriven shaft, a couplingmember, a member-adapted to receive torque from the driving shaft andtransmit said torque to said coupling member, said members beingprovided with cooperating helical teeth whereby said second mentionedmember is capable of limited rotative and translational movements withrespect to said coupling member, resilient means opposing said relativemovements, and means for transmitting said torque from said couplingmember to the driven shaft.

3. In a device for coupling a driving and a driven shaft, a couplingmember, .a member adapted to receive torque from the driving shaft andtransmit said torque to said coupling member, said members beingprovided with cooperating helical teeth whereby said second mentionedmember is capable of limited rotative' and translational movements withrespect to said coupling member, a spring adapted to be compressed upontranslational movements of said second mentioned member, whereby saidmovements are opposed by saidspring, .and means for transmitting saidtorque from said coupling member to the driven shaft.

4. In a device for coupling a driving and a driven shaft, a hub securedto the driving shaft, a coupling member, resilient means fortransmitting torque from said hub to said member, said resilient meanscomprising cooperating helical teeth formed upon said hub and saidmember, whereby said hub is capable of limited rotative andtranslational movement relative to said member, and resilient meansopposing said movemerit, a second hub secured to the driven shaft, andmeans for transmitting torque from said member to said second hub.

5. In a device for coupling a driving and a driven shaft, a hub securedto the driving shaft and provided with helical teethupon its periphery,a coupling member surrounding said hub and provided with cooperatinghelical teeth upon its inner surface, said member and hub being adaptedfor relative longitudinal movement, a second hub secured to the drivenshaft, means having flat surface engagement interposed between said hubsfor resiliently and frictionally resisting relative movement between thesaid member and first mentioned hub, and means for transmitting florlquefrom said coupling member to said second 6. In a coupling for drivingand driven members a rigid coupling member, an element rotatable witheach shaft and capable of limited rotational and axial movement withrespect to said coupling member, and resilient means surrounding saidelements and extending axially thereof adapted to be stressed byrelative movement of said elements upon rotation of the driving memherin either direction.

7. In a coupling for a pair of shafts a coupling member, an elementrotatable with each shaft and capable of limited rotation with respectto said member, and resilient means comprising telescoping rings adaptedto be wedged together and have energy stored therein upon relativemovement of either of said'elements and said to stretch certain of saidrings and compress others and simultaneously to set up friction betweenthem thereby damping the oscillations of the coupling.

9., A resilient and pair of shafts comprising a coupling member, andmeans connecting said member with each of said shafts, said meansincluding a series of unbroken, telescoping rings adapted to be forcedinto frictional engagement and devices for forcing said rings togetherupon rotatlon of said shafts in either directions.

10. A resilient and damping coupling between a pair of shafts comprisinga coupling member, an element connected for rotation with each of saidshafts, said elements being shiftable toward each other by said memberuponrotation of the shafts in either direction and reislient meansstressed,

upon shifting of said elements toward each other and storing energy inproportion to the torque transmitted between said shafts, said meansdissipating a portion of said energy in friction upon a reduction in thetorque.

11. In a device of the class described, a driving member, a drivenmember, and a flexible driving connection between said memberscomprising resilient means adapted to be stressed upon relative rotationof said members in either direction, said means including a plurality ofseparate friction elements with parallel friction-faces movable bodilyrelative to each other to damp and prevent rapid oscillation of saidconnection in response to minor fluctuations in torque.

12. A resilient and damping coupling between,

adriving member and a driven member comprising a plurality of unbroken,resilient rings having inclined surfaces adapted to be wedged together,and means operated by relative turning between said driving and drivenmembers in response to variations in torque for wedging said ringstogether, the friction between said rings serving to damp theoscillations of the coupling.

13. A resilient and damping coupling between amping coupling between aresponse to variations in torque and creating friction for dissipatingthe stored energy.

14. In a device of the class described a driving member, a drivenmember, and a flexible driving connection between said memberscomprising an element connected positively with one of said members forrotation therewith, means connecting said element with the other of saidmembers, said means including a part having limited rotational andlongitudinal movement relative to one of said members, and meanscomprising elements having parallel faces in fiat surresiliently andfrictionally resisting said relative movement.

15. In a device of the class described, a driving member, a drivenmember, and a flexible driving connection between said memberscomprisinga plurality of separate, axially shiftable resilient means adapted to bestressed upon relative rotation of said members, said means havingparallel faces arranged to be brought into frictional engagement uponrelative rotation of said members to damp and prevent rapid oscillationof said connectionin response to minor fluctuations in torque.

16. A resilient and damping coupling between a pair of shafts comprisinga rigid coupling memher, an element connected for rotation with each ofsaid shafts, said elements being confined within saidmember andshiftable toward each other by said member upon the driving of either ofthe shafts in either direction, and resilient'means for resisting saidrelative shifting of the elements.

, GUSTAVE FAST.

face contact cooperating with said elementfor/

